Known in the art, there is the U.S. Pat. No. 4,913,258 of Hiroshi SAKURAI et al, granted on Apr. 3, 1990, in which there is described an outer-rotor type motor wheel, comprising a knuckle, a hub coaxially interlocked with the knuckle, a wheel disc rotatably attached to the periphery of the hub, a wheel secured to the periphery of the wheel disc, a rotor fastened to an outer side of the wheel disc from the direction of the outer side, and a stator coaxial to and spaced from the rotor by a small gap and fastened to the hub from the direction of the outer side. One drawback with this outer-rotor type motor wheel, is that in order to provide a powerful motor wheel having a high torque, high current has to be injected to the power line to energize the coil of the armature core even at zero speed. With this outer-rotor type motor wheel, a converter has to be provided. This converter is mounted inside the vehicle and can be very cumbersome. Such high current circulating through the power line produces heat which is energy loss and also requires a power line which can be quite heavy.
Also known in the art, there is the U.S. Pat. No. 754,802 of Ferdinand PORSCHE et al, granted on Mar. 15, 1904, in which there is described the combination of the axle, the wheel, the hollow journal for the wheel, the end of the axle projecting to the journal, and a pivotal connection between the axle and journal having its axial line disposed acutely to the plane of the wheel. Again, to produce a powerful motor-wheel, the current supplied to the sliding brushes, brought from outside of the motor-wheel has to be a high current. This high current will have to be brought through large diameter cables or wires to reduce energy loss.
Also known in the art, there is the U.S. Pat. No. 2,348,053 of J. E. BOWKER, granted on May 2, 1944, in which there is described an electrically-operated motor vehicle improvements comprising a plurality of wheels arranged to be driven, a dynamotor forming an integral part of each such wheel, and electrical circuit connections between switch banks and dynamotors and batteries to control the operation of the dynamotors as motors according to the position of a selector switch. Again, the armature windings will have to be energized with a high current in order to produce a powerful motor, such high current will require large diameter cables to bring the energy from the batteries of the vehicle to the windings of the armature. As well known, such large diameter cables or wires are rigid, cumbersome and inconvenient.
Also known in the art, there are the following U.S. Pat. Nos. that describe different kinds of motor-wheels 638,643; 643,854; 2,348,053; 2,506,146; 2,514,460; 2,581,551; 2,608,598; 3,566,165; 3,704,759; 3,792,742; 3,812,928; 3,892,300; 3,897,843; 4,021,690; 4,346,777; 4,389,586; 1,709,255; 2,335,398; 3,548,965; 4,913,258.
None of the above-mentioned patents shows the necessary means for preventing presence of dirt and unwanted impurities between the housing of the rotor and a rim fixed around an outer surface of the housing.
It is an object of the present invention to provide an electrically motorized wheel assembly comprising a means for preventing presence of dirt and unwanted impurities between the housing of the rotor and a rim fixed around the outer surface of the housing.